Association of Low Back Pain Beyond Mid-Pregnancy with Maternal Physical Activity Prior to Pregnancy: A Cross-Sectional Study

Objective: 1) To compare the proportions of low back pain (LBP) in pregnant women with adequate and inadequate physical activity (APA and IPA, respectively) prior to pregnancy. 2) To identify possible factors associated with LBP during pregnancy. Material and Methods: A cross-sectional analytic study was conducted. Pregnant women answered questions about their physical activity prior to and during pregnancy, using the Thai version of the short International Physical Activity Questionnaire (IPAQ), and assessed their lower back pain via the visual analog scale and the Thai version of the Oswestry Disability Index (ODI). Results: A total of 342 pregnant women were enrolled. APA and IPA prior to pregnancy were detected in 172 and 170 cases, respectively. The proportions of LBP during pregnancy in each group were 61.6% and 64.7%, respectively. No statistically significant difference was found between the two groups (p-value=0.555). When adjusted with multiple factors in logistic regression model, APA prior to pregnancy decreased the risk of LBP during pregnancy (p-value=0.02), with an adjusted odds ratio (aOR) (95% CI) of 0.51 (0.281–0.916). In contrast, APA during pregnancy (p-value=0.01), pelvic pain (p-value<0.001), and LBP in a previous pregnancy (p-value<0.001) increased the risk of LBP during pregnancy, with aORs (95% CI) of 2.53 (1.236–5.197), 4.83 (2.563–9.110), and 7.49 (3.390–16.570), respectively. Conclusion: APA prior to pregnancy and limiting some types of activity during pregnancy may have a protective effect on LBP during pregnancy.